Waveguide phase shift actuator

ABSTRACT

An actuator for shifting the phase of an electromagnetic wave inside a waveguide. A worm gear connection controls the input to the actuator and drives a slide in a bi-directional movement. This slide is connected to a platform that controls the position of rods inside the waveguide. The position change of the rods in the waveguide causes a shift in the phase of the electromagnetic wave in the waveguide.

States Patent 1 1 1 1 9 Bushnell Apr. 17, 1973 [54] WAVEGUIDE PHASE SHIFT 2,955,268 10/1960 Rlblet ..333/81 B ACTUATOR 3,451,276 6/1969 Wadlow et a1 ..74/50 [75] Inventor: William H. Bushnell, Liverpool, FOREIGN PATENTS OR APPLICATIONS N'Y' 655,881 8/1951 Great Britain ..333/98 R [73] Assignee: The United States of America as 1,101,035 3/1961 Germany ..74/50 b th Secretary of th 235 y e i OTHER PUBLICATIONS IBM Tandem Scotch Yoke Assembl IBM Tech.

1 d: N 4, 1971 1 y [22] e Disclosure Bull. v01. 2 No. 5, 2-1960 p. 10. 21 App1.No.: 195,765

Primary Examiner--Rudolph V. Rolinec Assistant Examiner-Wm. H. Punter [52] US. Cl. ..333/98 R, 333/97 R, 74/50 51 1m. (:1 ..l-l0lp 1/00, Fl6h 21/24 wngh [58] Field of Search ..74/89.14, 50;

333/31 A 98 R [57] ABSTRACT An actuator for shifting the phase of an electromag- [56] References Cited netic wave inside a waveguide. A worm gear connection controls the input to the actuator and drives a UNITED STATES PATENTS slide in a bi-directional movement. This slide is con- 2,775,741 12/1956 Corbell ..333 31 A nected to a Platform that controls the Position of rods 2,307,174 1/1943 Wachs ..74 50 inside the waveguide. The position change of the rods 2,660,086 11/1953 Foreman etal ..74/23 X in the waveguide causes a shift in the phase of the 2,774,946 12/1956 McGillem et a1. ....333/98 R electromagnetic wave in the waveguide, 2,888,598 5/1959 Palluel ....333/3l A 2,697,209 12/1954 Sichak et a1. ..333/31 A 1 Claim, 2 Drawing Figures PATENTEDAPR 1 1191s 3, 728,647

William H. Bushnell,

Mm awzzu WAVEGUIDE PHASE SHIFT ACTUATOR BACKGROUND OF THE INVENTION This invention relates to the field of waveguide phase shifter actuators. Prior actuators are susceptible to vibration thus causing the phase shifter to move inadvertently. Also these actuators have a limited adjustment range for their output.

SUMMARY OF THE INVENTION This invention has provided a waveguide actuator less susceptible to vibration by the use of a worm input drive. Higher resolutions can be achieved because the adjustment point can be set near either end of slide movement without difficulty in locking up at the ends of travel because of the worm drive. Furthermore the bi-directional output of the rod actuator slide is correlated, by an indicator, to rods extending into the waveguide thereby giving better resolutions to the wave traveling in the waveguide and eliminates guess work.

This invention may be better understood from the following detailed description taken in conjunction with the accompanying drawing.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a partial sectional view of a waveguide actuator attached to a waveguide.

FIG. 2 is a partial sectional view of the adjusting mechanism of the actuator.

DESCRIPTION OF THE PREFERRED EMBODIMENT In FIG. 1, reference numeral indicates a waveguide for electromagnetic waves. A phase shift actuator 12 is mounted on the waveguide by appropriate means and includes a platform 14 secured to said actuator by means 16. This platform supports phase shifting rods 18 which project through openings 20 into the waveguide. When the platform is raised or lowered the position of the rods inside the waveguide will be varied. The position change of the rods varies the volume of the waveguide and hence causes a corresponding shift in the phase of the electromagnetic wave traveling therein.

The actuator is more clearly shown in FIG. 2 and includes a member 22 for housing a rotatable worm drive 24. The actuating force for the worm drive is a knob 26 which when moved causes rotation of the worm drive in response to whatever direction the knob is moved. As the worm drive rotates it meshes with and drives gear 28 around its shaft 30 which is supported in the housing 22. A guide 32 is mounted on housing 22 by means 34 and provides support for slide 36 which is located adjacent said gear. The guide includes grooves 38 which mate with bevelled edges 40 of the slide for controlled movement of the slide. An elongated slot 42 is provided in the slide for engagement with a crank pin 44 that is mounted off center on one face of gear 28. This type of connection provides the means whereby the slide is raised or lowered from a neutral position whenever the worm drive 24 is rotated. An indicator 46 is mounted on housing 22 for correlating the slide bidirectional output to the position that the rods extend into the waveguide. Therefore turning knob 26 causes a proportional change in the relative position ofthe rods within the waveguide and a proportionate shift in the phase of the wave.

The operation of the phase shift actuator is as follows: movement of knob 26 causes rotation of worm drive 24 and a corresponding rotation of gear 28. Crank pin 44, attached to gear 28, in turn moves slide 36 from a neutral position to a position selected by the knob. The extent of slide movement is limited by either end of slot 42. Thus it can be seen that the slide can be reciprocated from a neutral point to a limit of motion on both sides of neutral providing a bi-directional motion. Movement of the slide directly raises or lowers the rods within the waveguide and hence shifts the phase of the electromagnetic wave traveling therein. Because of the bi-directional motion of slide 36 higher resolutions of phase shifting can be achieved since the adjustment point can be set near either end of the slide motion. The use of a worm drive results in an output of the slide that is less susceptible to vibrations which previously caused the phase shift actuators to move inadvertently. In addition the worm drive allows higher resolutions since there is no lock up at the ends of slide movement.

Iclaim:

l. A waveguide phase shift actuator for shifting the phase of an electromagnetic wave in a waveguide having openings therein, said actuator comprising: a platform for supporting a plurality of phase shifting rods, said rods projecting through said openings and into said waveguide; means for producing bi-directional movement, said means connected to said platform for moving said rods in said waveguide to shift the phase of the electromagnetic wave traveling in said waveguide, said means including a slide connected to said platform; a guide for mounting and controlling movement of said slide; said slide being provided with an elongated slot; a rotatable gear disposed adjacent said slide and provided with a crank pin mounted off center on the face of said gear, said crank pin engaging said slot for imparting a driving motion to said slide; drive means disposed in a housing means, said drive means positioned juxtaposed to said rotatable gear for imparting movement thereto, thereby moving said rods, said drive means including a worm gear having a knob for actuating said worm gear; and an indicator mounted on said housing for correlating the slide bi-directional output to the rod position in said waveguide. 

1. A waveguide phase shift actuator for shifting the phase of an electromagnetic wave in a waveguide having openings therein, said actuator comprising: a platform for supporting a plurality of phase shifting rods, said rods projecting through said openings and into said waveguide; means for producing bi-directional movement, said means connected to said platform for moving said rods in said waveguide to shift the phase of the electromagnetic wave traveling in said waveguide, said means including a slide connected to said platform; a guide for mounting and controlling movement of said slide; said slide being provided with an elongated slot; a rotatable gear disposed adjacent said slide and provided with a crank pin mounted off center on the face of said gear, said crank pin engaging said slot for imparting a driving motion to said slide; drive means disposed in a housing means, said drive means positioned juxtaposed to said rotatable gear for imparting movement thereto, thereby moving said rods, said drive means including a worm gear having a knob for actuating said worm gear; and an indicator mounted on said housing for correlating the slide bi-directional output to the rod position in said waveguide. 